Low voltage guide light



Jan. 15, 1957 w, MOELLER I 2,777,943

LOW VOLTAGE GUIDE LIGHT Fild Sept. 9, 1955 IN VEN TOR.

4&7/109 M/ 440544.52, 60 5 J BY ATTOENEY 2,777,943 7 LOW VOLTAGE GUIDE LIGHT Arthur W. Moeller, Waterloo, Iowa Application September 9, 1955, Serial No. 533,452 2 Claims. (Cl. 240--52) This invention relates to a small, low voltage light, adapted to be mounted in a wall surface or in any other desired location, and so designed as to represent a mini-' mum projection from said surface, while still providing suflicient light to illuminate a nearby area.

The desirability of a light of the type referred to can be readily appreciated, when it is kept in mind thatin many locations in the home, or in many other situations, the need for a small, continuously burning light is quite pronounced. For example, keyholes of doors are often disposed where they cannot be readily located in darkness, and under these circumstances it is highly desirable that a small, continuously burning light be located in close proximity to the keyhole, so as to fully illuminate the same, thus facilitating the insertion of the key. Additionally, many stairways are dark, and as a result, accidents tend to occur when a stair tread is missed while one is ascending or descending the stairway in darkness.

In still another situation, it is desirable to keep a small light burning in a childs room, so as to provide a light so that one may, in apparent emergency situations arising during the night, move swiftly and without possibility of accident to the child. Other situations, of

course, develop in which a small, low voltage light is desirable for the purpose of providing illuminationin particular areas and in particular situations.

The main object of the present invention is to provide a light having the characteristics noted as desirable in the preceding paragraphs. To this end, the'light constituting the present invention includes a lamp assembly adapted to be mounted in an opening formed in a selected supporting surface, as for example, the door jamb located adjacent a keyhole, with said lamp assembly being particularly designed to be illuminated by low voltage, through the medium of a transformer converting the voltage of a conventional domestic electric supply to a relatively small number of low volts, so low as to permit the lamp to be permitted to burn continuously without fear that an excessvie amount of electric power will be used.

Another object of the invention is to'provide 'a device of the nature referred to which can be manufactured at relatively low cost, will be highly efiicient when in use, and will be so inconspicuous as not to be readily noticed during the daytime hours.

Other objects will appear from the following description, the claims appended thereto, and from the annexed drawing in which like reference characters designate like parts throughout the several views and wherein:

Figure 1 is a perspective view showing a doorway in which is mounted a lamp assembly formed according to the present invention;

Figure 2 is an enlarged sectional view on line 22 of Figure 1;

Figure 3 is a longitudinal sectional view through the lamp assembly; and

Figure 4 is a diagram of the electric wiring employed in the invention.

Referring to the drawings in detail, the lamp assembly can be mounted wherever desired, and is illustrated in position adjacent a keyhole purely for the purpose of showing one of many uses of the invention. Thus, in the illustrated example, there is shown a doorway including a side jamb 12, a door 10, and a keyhole and door knob assembly 14.

The lamp assembly constituting the present invention has been generally designated at 16, and includes a cylindrical, metallic casing 18 adapted to be recessed within the door jamb 12, the door jamb being bored to receive the lamp assembly as shown in Figure 3.

The casing 18, at its front end, is integral with a head casing portion 20, having threads formed in the same, said threads being engageable in complementary threads provided in the bore of the side jamb 12. At its front end, the enlarged, threaded portion 20 of the casing merges into a circumferential bead or rolled lip 22 which is adapted to define a collar limiting threading of the portion 20 inwardly of the side jamb, said collar engaging against the outer surface of the side jamb as shown in Figure 3.

At its rear or inner end, within the door frame, the cylindrical casing 18 has an inwardly turned, circumferential lip 24. Bearing at one end against the lip, and lining the interior of the casing 18, is a sleeve-like liner 26 of electrically insulative material, having at its front end an outwardly directed flange portion 28 bearing against the shoulder defined at the inner end of the em larged casing portion 20.

The liner spaces from the casing 18 (which may be appropriately termed an outer casing), a metallic, electrically conductive inner casing 30 having a front end disposed within the enlarged casing portion 20, said front end having an outwardly directed circumferential flange 32. Bearing against the flange is an annular washer or spacer 34 of electrically insulative material, the spacer being interposed between the flange 32 and a collar 36 provided at the base of a low voltage electric lamp bulb 38, the bulb 38 having a cylindrical, axial extension 39 A plastic cover 37 for the bulb is threaded toengage internal threads of casing portion 20, to force the collar 36 against spacer 34. This in turn, by a clamping action exerted by collar 36 and the inner end of enlarged, threaded portion 20, holds the liner, inner casing, and spacer assembled with the outer casing.

At its rear end, the inner casing 30 is formed open, and at one side has an inwardly turned lip 40. At the other side, casing 30 is integrally formed with an elon gated prong element or tongue 42 projecting beyond the inner end of the outer casing 18.

Within the rear end portion of the inner casing 30 there is provided a cylindrical block 44 of electrically insulative material, axially bored to receive an electrically conductive rod 46 in contact at its head end with the base terminal 47 of the electric lamp bulb, the electrically conductive side wall of the extension 39 con- .stituting the other terminal of the lamp bulb and being in engagement with the inner casing 30.

At its other end, rod 46 is provided with a nut 48 threaded upon the rod and bearing against a lateral extension of a second tongue or prong 52. Interposed be tween the lateral extension of tongue 52 and the lip 40 of the inner casing 30 is a washer 50 of electrically consuitable source of electric power, and constituting part I of the normal house wiring, usually at approximately 110 volts. The connection is made at a receptacle 70 of the house wiring system.

The voltage .can he stepped down by the transform r 58 to any extent desired, and in :a preferred embodiment, would he stepped down to 3-6 volts. Of course, the voltage supplied to the primary winding of the transformer and the voltage flowing to the ,lamp bulb 38 will differ in various localities, it being mainly important to note that the lamp assembly is so designed as to use a very low voltage, permitting the lamp bulb to be energized continuously without fear of excessive use of electrical power.

In use, the lamp bulb when energized will illuminate an adjacent area, at low cost and as shown in Figure 1, can he used to provide illumination tor a keyhole, so that a key-can be inserted without ones having to gnope tor the keyhole. Alternatively, the lamp, {or a plurality of the lamps, can be used on dark stairways, or in other dark areas to provide continuous illumination with-out {H6965- sity of groping for a light switch It is [believed apparent that the invention :is not neces sarily confined tothe specificiuse or uses thereof described above since it may be utilized for any purpose .to which it may be suited. Nor {is the invention to be necessarily limited to the specific eonstnuction illustrated and adescribed, Since such construction is only intended :to [be illustrative of the principles in construction that may he permitted within the scope of the appended claims.

W118i is claimed is:

l. A lamp assembly compnisiug :an outer casing of cylindrical formation, said casing being fonmed at one end a portion threaded both internally and external- 1y; -,a lain-p bulb engaged in one end of Ithe'outer casing and including an electrically conductive .side wall and a base terminal; on inner casing receiving the electrically eouductue side "wall of the lamp bulb and disposed in electrical contact with said side wall, said inner easing being spaced inwardly iromthe wall of the outer casing; an electrically insulative liner of cylindrical formation interposed between the outer and inner casings in .the space between :the same, said inner casing at one end including an elongated, electrically conductive tongue pnojecting beyond theother end of the outer-casing; a block (of electrically insulative material confined within the -i-uma casing, said block :at one end being engaged by one end of :the inner casing and terminating at its other end adjacent the base terminahof the bulb; an electrically-conductive trod extending .a-x ially of and within the block, said rod projecting at its opposite ends beyond opposite ends of the block with one end of the rod being engaged against the :base :tenminal of the bulb; a tongue secured to the other end of the rod and projecting beyond said other .end not the outer casing in laterally spaced relatitm do the first named tongue, for connection of a pair ofielectnical leads to the respective tongues, the lamp bulb including :a circumferential collar and said inner casing heingrformed at one end with an outwardly directed lip, the-lamp assembly including an annular, electrically inisulatiue'awasher extending about the-side --wall of the bulb and interposed between the collar of said bulb andsaid lip ofthe increasing, and a cover for the bulb threaded to engage the internal threads of the casing portion, said cover bearing against the collar of the bulb to shift the same axially within the outer casing, thereby to tightly bindagainst each other the lip, washer, and bulb.

2. A lamp assembly comprising an outer casing of cylindrical formation, said casing being formed at one end with a portion threaded both internally and external- 1y; a lamp bulb engaged in one end of the outer casing and including an electrically conductive side wall and a base terminal; an inner casing receiving the electrically conductive side wall of the lamp bulb and disposed in electrical contact with .said side wall, said inner easing being spaced inwardly from the wall of the outer casing; an electrically insulativeliner of cylindrical formation interposed between the outer and inner casings in the space between the same, said inner casing at one end including an elongated, electrically conductive tongue projecting beyon the other end of the outer casing; a blo k Qfele .trically insulative material confined within the inner teasjug, said block at one end bein engaged by one @335 of the inner easing; d terminating at its o her and adja ent the base terminalof the bulb; an electrically conductive rod extending axially of and within the block, said rod projecting at its opposite ends beyond opposite ends of the block with one end of the rod being engaged against the base terminal of the bulb; a tongue secured to :the other end of the rod and projecting beyond said otherend of the .outer casing in laterally spaced relation :to the first named tongue, for connection of a pair of electrical leads :to the respective tongues, the lamp bulb including a eircumierential collar and said inner casing being formed at one end with an outwardly directed lip, the lamp as- .sembly including an annular, electrically insulative washer extending about the side wall of the bulb and interposed between the collar of said bulb and said lip of the inner casing, and a cover for the bulb threaded :to engage the int nnal threads :Qf the casing portion, said cover bearing against the collar of :the abulb :to shift ihe same within the .outer casing, thereby to tightly .bind against each ntherithe lip, washer, and :bulb, said .casing portion being (of greater diameter {than the remaining portion of dhe mltertcasing 310 define a shoulder, ,at the inner end of the threaded casing portion, .said diner :being tor-med with can-outwardly directed flange portion bearing against the ehotilder the slip of the inner teasing: being interposed between the iflange portion of the liner and said collar, whereby to .clampably engage between the collar and .ehouldersa'id washer, lip, and the flange portion of the liner responsive 10 threading .of the bulb cover into the threadedscasingpontion.

dl fiereuces ;Cited:in;the .fileof this patent UNITED STATESPATENTS 

